Video progress: different orange on dark mode

When using the dark mode, the video progress bar doesn't use the same orange as the one used in other components

EDIT: in fact, it's the same in the bright mode

changed the description

changed milestone to %3.3.0

added Beginner friendly MediaLibrary Minor labels

I have tried to update the colour of the Progress Bar as well as elapsed time label to match that specific orange colour used across the application. I have put up a pull request #447 (closed) on github, kindly go through and provide some feedback.

closed with commit 7b1e2548

The pull request was OK and merged manually without the unneeded merge commit. Please consider creating a merge request on this gitlab for future contributions. Thank you.

assigned to @fkuehne